It is not that hard for C++ developers to pick up Rust. The borrow checker makes explicit safety requirements that exist in C++.
The tooling does need to be more mature but for many projects the pioneer tax paid to improve the tooling may be worth it. Besides, it's not as if C++ dependency management is very mature either — most people build custom tooling for that anyway.
The tooling does need to be more mature but for many projects the pioneer tax paid to improve the tooling may be worth it. Besides, it's not as if C++ dependency management is very mature either — most people build custom tooling for that anyway.